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How Much Chlorine Should You Add to Your Pool?

Having clean, safe, and beautiful water is every pool owner’s dream. In order to get that, you need to sanitize the pool. Using chlorine is one of the most common methods for killing bacteria, destroying algae, and oxidizing other non-living organic contaminants like sweat, body oils, detergents, cosmetics, and more. But just how much chlorine do you need to add to the pool to keep it safe for swimming? How many chlorine tablets do you need for your pool each week? What about liquid chlorine or chlorine granules — what's the correct dosage? We've put together an easy-to-read chart that helps you calculate how much you should to add to your pool. This helpful chlorine dosage chart breaks it down by the different types of chlorine in relation to the size of your pool. The dosages below are generally recommended amounts of chlorine needed for routine maintenance.

Here are a few tips before we dive into the chart:

  1. If you are using chlorine products as your primary sanitizer, we recommend maintaining a residual chlorine level of 1–4 ppm to effectively kill bacteria and prevent algae.
  2. You may want to adjust the chlorine quantity depending upon the weather and your pool usage patterns. Warmer temperatures, stormy weather, and extra swimmers will require more sanitizer to keep the water clean and healthy.
  3. Chlorine works most effectively in well-balanced water, so it's important to test your pool water at least once per week during swimming season. Stop by your local Leslie’s for a FREE AccuBlue® 10-point water test, or use an at-home water test kit. This will help you understand your pool’s chemistry levels, as well as highlight the current Free Chlorine level.

Product Type % Available Chlorine FAC Increase Application 5K Gal. 10K Gal. 15K Gal. 20K Gal. 25K Gal. 30K Gal.
Leslie's 3" Jumbo Tabs Trichlor 90% Maintain 1–4 ppm Chlorinator, Weekly Refill 1 Tab 1–2 Tabs 2–3 Tabs 3–4 Tabs 4–5 Tabs 5–6 Tabs
Leslie's Chlor Brite Dichlor 55% 1 ppm Routine Sanitizer, As Needed 1.5 Oz. 3 Oz. 4.5 Oz. 6 Oz. 7.5 Oz. 9 Oz.
Leslie's Chlor Brite Dichlor 55% 6.8 ppm Weekly Shock Treatment 10.5 Oz. 21 Oz. 31.5 Oz. 42 Oz. 52.5 Oz. 63 Oz.
Leslie's Power Powder Plus Cal-Hypo 70% 5 ppm Weekly Shock Treatment 4.5 Oz. 9 Oz 13.5 Oz. 18 Oz. 22.5 Oz. 27 Oz.
Leslie's Chlor Sticks Trichlor 90% Maintain 1–4 ppm Chlorinator, Weekly Refill 1 Stick 1–2 Sticks 2–3 Sticks 3–4 Sticks 4–5 Sticks 5–6 Sticks
Leslie's Liquid Chlorine Sodium Hypochlorite 12.50% 1 ppm Routine Sanitizer, As Needed 5 Fl. Oz. 10 Fl. Oz. 15 Oz. 20.5 Oz. 25.5 Oz. 31 Oz.
Leslie's Liquid Chlorine Sodium Hypochlorite 12.50% 6 ppm Weekly Shock Treatment 0.25 Gal. 0.5 Gal. 0.75 Gal. 1 Gal. 1.25 Gal. 1.5 Gal.
Leslie's Fresh 'N Clear MPS 0% 0 ppm Weekly Oxidizing Treatment 0.5 Lbs. 1 Lb. 1.5 Lbs. 2 Lbs. 2.5 Lbs. 3 Lbs.

This chart is used for routine chlorine applications and weekly maintenance, so remember to adjust your sanitizer levels during the peak season or as often as needed in order to maintain a Free Available Chlorine level between 1–4 ppm. If your Total Available Chlorine level is more than 0.3 ppm above your Free Available Chlorine level, your pool is due for a shock treatment to get rid of the accumulating chloramines (Combined Chlorine) in the water. When using any pool chemical, always carefully read and follow product label instructions to ensure proper application techniques and dosage recommendations for your pool.

Once you know how much chlorine to add to the pool, it's important to make sure your water is properly balanced. Well-balanced water ensures your sanitizer can work as efficiently as possible, and will ultimately help your chemical budget go further. Stop by your local Leslie's for a FREE in-store AccuBlue® water test to assess 10 of the most important aspects of water chemistry. In just 60 seconds, you'll also receive an easy-to-follow, step-by-step water treatment plan that's customized to your pool. Our friendly in-store experts can also provide insights on which chlorine types will work best for your pool's needs.

Top Products

Leslie's 3 inch Chlorine Tablets

Chlorine Tablets


Pool Sanitizers

Leslie's Pool Shock

Pool Shock

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Leslie’s makes every effort to provide accurate recommendations based upon current ANSI/APSP/ICC-5 2011 (R2022) standards, but codes and regulations change, and Leslie’s assumes no liability for any omissions or errors in this article or the outcome of any project. You must always exercise reasonable caution, carefully read the label on all products, follow all product directions, follow any current codes and regulations that may apply, and consult with a licensed professional if in doubt about any procedures. Leslie’s assumes no legal responsibility for your reliance or interpretation of the data contained herein, and makes no representations or warranties of any kind concerning the quality, safety, or suitability of the information, whether express or implied, including, without limitation, any implied warranties of merchantability or fitness for a particular purpose.